The structure core provides instrumentation and expertise for all projects that use either X-ray crystallography or NMR spectroscopy. It combines the resources of the Stroud and Doetsch laboratories and their capabilities in structural biology. Dr. Robert Stroud will direct efforts to express proteins, purify them, characterize them as to monodispersity and aggregation state , and crystallize proteins and complexes for x-ray diffraction. The crystal structures will be determined by X-ray diffraction methods under Dr Stroud's direction. Dr. Volker Doetsch will direct NMR spectroscopy experiments, both in terms of high-resolution structure determination and characterization of ligand binding and protein dynamics. The structure core provides laboratories that are equipped for large scale production and purification of proteins for structural investigations. In addition, specialized equipment, including x-ray detectors, access to synchrotron beamlines and NMR instruments ranging from 400 MHz to 600 MHz are part of this core. The structure core will facilitate the coordinated expression of the multi-milligram quantities of proteins needed for both X-ray crystallography and NMR. In particular it will be involved in the structure determination of HIV integrase, HIV protease, KSHV proteases, alkylhydroperoxidase C and peptide-RNA complexes between Jembrana disease virus Tat protein and JDV and BIV TAR. For some of these proteins small molecule inhibitors exist and the core will obtain and so provide structural information on the interaction of these inhibitors with their targets. The experiments will include both structural investigations, mainly by X-ray crystallography, and dynamic investigations by NMR spectroscopy. In the case of the HIV protease this combined approach will provide information about the binding mode of different classes of inhibitors. For other proteins for which no inhibitors are available yet, the core will support the search and development of potential small molecule inhibitors by providing structural and dynamic information as well as NMR screening assays that can detect interaction between small molecules and the protein.